Method and apparatus for connecting rails

ABSTRACT

An apparatus for connecting abutting rail ends which are electrically isolated from one another comprises a cast tie having a pair of spaced-apart elongate support members cast into it. First and second yoke members are attached to both of the support members in a manner such that they are electrically isolated from the support members. A first clamp member associated with the first support member can be attached to both sides of the first rail end, and a second clamp member associated with the second yoke member can be attached to both sides of the second rail end. The yoke members are cast into the tie in a manner such that they are electrically isolated from one another and from the tie. The resulting structure not only holds the rail ends rigidly with respect to one another but also holds them rigidly with respect to the tie.

BACKGROUND OF THE INVENTION

It is common to use railroad rails to transmit a signal to or from atrain. Typical reasons for doing this are to advise the engineer ofswitch positions and to remotely monitor the location of the train. Thisrequires the rails to be broken at periodic intervals and that theresulting rail ends are electrically isolated from one another. This isaccomplished by fabricating track sections having electrically isolatedrail ends and installing them at the desired locations. Due to thesevere loads placed on the rails by trains running on them, the flangesof the rail ends need to be rigidly tied together. This has been done inthe past by placing tie plates which are surrounded by anon-electrically conductive coating across the rail ends on each side ofthe flange and bolting them to the flange and to one another. Whilethese prior art tie plates do substantially eliminate relative movementbetween the abutting rail ends, they still allow some movement of therail ends which with time causes the plastic insert that is placedbetween the rail ends to wear, causing these track sections to have alimited life.

BRIEF SUMMARY OF THE INVENTION

The subject invention provides a cast tie having a pair of spaced-apartelongate support members cast into it. First and second yoke members areattached to but electrically isolated from both of these supportmembers. A first clamp member associated with the first yoke member isattachable to a first rail end, and a second clamp member associatedwith the second yoke member is attached to a second rail end which abutsthe first rail end but is electrically isolated from it. The yokemembers are cast into the tie in a manner such that they areelectrically isolated from the tie and from each another.

The foregoing and other objectives, features, and advantages of theinvention will be more readily understood upon consideration of thefollowing detailed description of the invention, taken in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a perspective view of a railroad track section embodying therail connection system of the subject invention.

FIG. 2 is an exploded perspective view of yoke members which are anelement of the invention.

FIG. 3 is a perspective view of the yoke members together.

FIG. 4 is a perspective view of the yoke members installed on supportmembers which are another element of the invention.

FIG. 5 is a perspective view showing how the track section of FIG. 1 ismade.

FIG. 6 is an exploded perspective view of the track section.

FIG. 7 is a perspective view of the track section.

FIG. 8 is a cross-sectional view, at an enlarged scale, of the tracksection.

FIG. 9 is a perspective view of an insulating spacer which is an elementof the subject invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Referring now to FIGS. 1-4 of the drawings, an apparatus for connectingaligned abutting rail sections which are electrically isolated from oneanother includes a pair of spaced-apart, side-by-side, elongate supportmembers 10. The support members shown in the drawings are individualmetal bars but many other materials and shapes would work as well.Examples are a bundle of fibers which are held in tension betweenbulkheads and a bundle of smaller diameter high strength tubes. Withbars of the type shown in the drawing, the support members are roughlyeight feet long, but the length would depend on the size of the bars andother design factors.

Mounted on the support members are a first yoke member 12 and a secondyoke member 14, FIG. 2. In the embodiment illustrated the yoke membershave two side-by-side feet 16 with openings 18 at each end which looselyreceive the support members 10. The feet 16 are joined together by aclamp member 20 which extends between the top surfaces 22 of the feet16. The clamp member 20 is located at one end of the feet 16. The firstyoke member 12 is reversed relative to the second yoke member, and oneof its legs 16 is inserted between the pair of legs of the second yokemember until the openings in the two yoke members are aligned, FIG. 3.The spacing between the legs is slightly less than the width of the legsso that no portion of the first yoke member is in contact with thesecond yoke member when they are in this position. The support membersare then inserted through the aligned openings 18. The support membersare joined to the yoke members by an electrically non-conductive joint24. In the preferred embodiment illustrated the joint 24 is a highcompression strength epoxy which is poured in the space between thesupport members 10 and the inner walls of the openings 18 in the yokemembers. A 20,000 PSI compression strength epoxy made by Loctite workswell for this purpose. The joint could also be a sleeve which isattached to both the support member and the joint member. Posts 25protrude from the support members and the yoke members to better embedthem into a cast tie, as will be explained later.

Located on one side of each clamp member 20 is a first leg 26 which isan integral piece of the clamp member. Located on the other side of theclamp member 20 is a platform 27 which has a second leg 28 removablyattached to it by means such as bolts 30, FIGS. 6 and 7. The top surfaceof the platform 27 and the bottom surface of the second leg 28 havemating discontinuous surfaces which prevent the second leg from movinglaterally relative to the platform. In the embodiment illustrated thisis accomplished by placing mating slots 32 in the platform and secondleg with keys 34 located in them. Aligned holes 35 extend through thefirst and second legs. The first and second legs are arranged to fitover the top of the rail base, and under the rail head on opposed sidesof the rail, FIG. 8. Typically there would only be a support member/yokemember assembly for one of the rails as shown in FIG. 1, but there couldbe an assembly under both rails if desired.

The support member/yoke member assembly is cast into a tie 36, FIG. 1.The tie includes a first section which comprises a pair of spaced-apart,side-by-side elongate legs 38. A second section of the tie comprises across member 40 which extends between the legs 38 below where the brokenrail crosses the tie. The legs 38 preferably are made of concrete, butcould be made from any material that is or later becomes common formaking cast railroad ties. The cross member needs to be electricallyisolated from the concrete legs and from the support members 40. One wayto accomplish this is to make the cross member from an electricallynon-conductive material. In a preferred embodiment the cross member 40is made from an epoxy grout. Because the epoxy is electricallynon-conductive and surrounds the support member/yoke member assembly itelectrically isolates the yoke members and support members from oneanother and from the concrete legs 38. The epoxy also rigidly connectsthe yoke members and the support members to the tie. In the embodimentillustrated the support members extend into the second section of thetie which further joins the entire device together. It is also possibleto make the cross member from a conductive material, such as concrete,and provide an electrically non-conductive barrier between the crossmember and the support members 10, yoke members 14 and legs 38.

Referring now to FIG. 5, the apparatus is made by assembling the supportmember/yoke member assembly and placing it in a form 42. The form has apartition 44 with holes extending through it that receive the supportmembers 10. The partition locates the support members 10 in the form.The partition also divides the form into a first section 46 in which thefirst section of the tie is cast, and a second section 48 in which thesecond section of the tie is cast.

In use the apparatus is placed under a pair of rails, at least one ofwhich has been cut to provide a break which electrically isolates therail end 50 on one side of the break from the rail end 52 on the otherside of the brake, FIGS. 6 and 7. The apparatus is located such that oneof the rail ends 50 extends across one of the clamp members 20 and theother rail end 52 extends across the other clamp member, with theflanges 55 of the rails placed against the first legs 26 of the clampmembers. The second legs 28 of the clamp members are then placed on theplatforms 27 against the opposed sides of the rail flanges, and areattached to the platforms by bolts 30. Bolts 54 are placed through theholes 35 in the legs 26, 28, and aligned holes (not shown) in the railflanges to clamp the rails between the opposed legs 26, 28.

As is standard with concrete ties, polyurethane tie pads 56 are placedbetween the bottoms of the rails and the tops of the clamps to cushionthe rails. In addition, a separator 58 made from a non-electricallyconductive material, such as plastic, is placed between the rail ends,FIG. 9. The separator has a notch 60 located in it and a tab 62, whichis attached to one of the clamp members by one of the bolts 30, fitsinto the notch and pushes the separator against one of the rails.Because the separator is held in place by the pressure of the tab it caneasily be replaced.

The terms and expressions which have been employed in the foregoingspecification are used therein as terms of description and not oflimitation, and there is no intention, in the use of such terms andexpressions, of excluding equivalents of the features shown anddescribed or portions thereof, it being recognized that the scope of theinvention is defined and limited only by the claims which follow.

1. Apparatus for connecting abutting rail ends comprising: (a) A casttie; (b) a pair of spaced-apart, elongate support members which are castinto said tie generally under where the rail ends cross said tie; (c) afirst yoke member which is attached to both of said support members in amanner such that said first yoke member is electrically isolated fromsaid support member; (d) a second yoke member which is attached to bothof said support members in a manner such that said second yoke member iselectrically isolated from said support members; (e) a first clampmember, associated with said first yoke member, which is attachable to afirst one of said rail ends; (f) a second clamp member, associated withsaid second yoke member, which is attachable to a second one of saidrail ends; and (g) said yoke members being cast into said tie in amanner such that they are electrically isolated from said tie and fromone another.
 2. The apparatus of claim 1 wherein said tie has a firstsection which electrically isolates said yoke members from one anotherand from the rest of said tie and a second section which forms the restof said tie.
 3. The apparatus of claim 2 wherein said first sectionsurrounds said yoke members.
 4. The apparatus of claim 3 wherein saidfirst section is epoxy grout.
 5. The apparatus of claim 4 wherein saidsecond section is concrete.
 6. The apparatus of claim 1 wherein said tiecomprises a pair of elongate spaced apart legs, and a cross member whichextends between said legs where a rail crosses said tie.
 7. Theapparatus of claim 1 wherein said first and second yoke members havealigned openings which said support members pass through.
 8. Theapparatus of claim 7 wherein said support members are elongate bars. 9.The apparatus of claim 7 wherein said yoke members are attached to andare electrically isolated from said support members by a highcompression strength epoxy which is placed between said yoke members andsaid support members.
 10. The apparatus of claim 1 wherein each saidyoke member comprises a pair of side-by-side feet which said openingsextend through.
 11. The apparatus of claim 10 wherein one foot of eachyoke member fits between the pair of feet in the other yoke member. 12.The apparatus of claim 11 wherein said clamp members are attached tosaid feet and the clamp member of the first yoke member is offset fromand separated from the clamp member of the second yoke member.
 13. Theapparatus of claim 1 wherein said clamp members have first legs whichare integral with the respective yoke members and second legs which arereleasably attached to the respective yoke member.
 14. The apparatus ofclaim 13 wherein the portions of said yoke members which said secondlegs attach to and said second legs have interfitting, discontinuoussurfaces which prevent movement of said second legs laterally withrespect to said yoke members.
 15. A method for making and apparatus forconnecting abutting rail ends comprising: (a) providing a mold formaking a tie, said mold having a first cavity configured to cast a pairof side-by-side legs and a second cavity which extends between said legsand is fluidly connected therewith; (b) placing a pair of elongatesupport members in said mold with one of said support members beinglocated in each leg; (c) attaching a pair of yoke members to both ofsaid support members with said yoke members being in said second cavity;(d) electrically isolating said support members from said yoke members;(e) filling said first cavity with concrete; and (f) filling said secondcavity with an electrically nonconductive material.
 16. The method ofclaim 15 wherein said support members are electrically isolated fromsaid yoke members by inserting a high compression strength epoxy betweenthem.
 17. The method of claim 15 wherein said electricallynon-conductive material is epoxy grout.
 18. The method of claim 15including the additional step of installing a rail clamp on each of saidyoke members.